Radiation therapy for mesothelioma uses energy to damage and kill cancer cells. It can also help stop the tumor from spreading. It is commonly used as part of a multimodality regimen in pleural mesothelioma. Radiation can relieve symptoms and prolong survival for mesothelioma patients.
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What Is Mesothelioma Radiation Therapy?
Radiation energy is used in radiation therapy for mesothelioma to kill cancer cells. Specifically, cancer-directed radiation therapy uses ionizing radiation. Ionizing radiation occurs in two main forms: photon radiation and particle radiation.
- The most popular type of radiation therapy for cancer is photon beam radiation. It uses the same form of radiation as X-rays but at a much higher dose. Photons can release energy at any point in their path, entering, passing, and leaving the body. Because of this characteristic, photon radiation can shrink tumors but also harm healthy tissue.
- Particle radiation uses electrons or protons to power cancer cells. Protons release energy only at a specific distance from their source. Proton radiation can therefore cause minimal tissue damage while killing cells at the end of its route. This characteristic might make photon beam radiation more harmful than proton radiation.
Note: Proton beam radiation requires specialized equipment. It is not yet widely available.
Some forms of radiation can deliver more energy to the tissues beneath the skin than others. Therefore, certain types of radiation may be more effective at targeting tumors that are distant under the skin. Radiation specialists look at the characteristics of each form of radiation. Doctors keep these properties in mind when prescribing radiation therapy. Radiation may prolonglife for some mesothelioma patients.
How Does Radiation Treat Mesothelioma?
Doctors use beams of radiation to damage the DNA in mesothelioma cells. When a cancer cell’s DNA is severely damaged, the cell dies and is no longer able to regenerate. This can help prevent metastasis or spread of mesothelioma.
In general, radiation affects fast-growing cells more than slow-growing cells. As a result, fast-growing cells, such as those in bone marrow and skin, may die soon after treatment. Slower-growing cells, such as those in the brain or nerves, may take longer to die. Damaged cells can continue to die for days, weeks, and months after radiation therapy.
Doctors may use radiation to remove mesothelioma cells. This is called therapeutic treatment. Doctors may also use radiation to minimize the symptoms of mesothelioma. Treatment that promotes symptoms and quality of life is called palliative treatment.
Which Forms Of Mesothelioma Receive Radiation Therapy?
Doctors and researchers have tested radiation therapy in all forms of mesothelioma. Radiation therapy has been shown to be beneficial in patients with pleural mesothelioma. However, it did not work well for patients with peritoneal mesothelioma.
Therefore, patients with pleural mesothelioma often receive radiation therapy, but patients with peritoneal mesothelioma do not.
Radiation As Part Of Multimodal Mesothelioma Therapy
Doctors often prescribe radiation therapy as part of a multimodality treatment plan for mesothelioma. Multiple mesothelioma treatment modalities, such as surgery, chemotherapy, and radiation, are combined in a multimodal approach. Research shows that multimodality therapy can lead to better survival in patients with mesothelioma.
Radiation can occur as a pre- or post-surgery therapy. In either case, the radiation energy can damage or kill tumor cells. This may delay or stop the spread of the tumor after surgery.
One of the most successful studies on the treatment of multimodal mesothelioma is the SMART trial. Surgery for Malignant Pleural Mesothelioma After Radiotherapy is referred to as SMART. Patients in the SMART trial received high-dose radiation therapy before surgery.
The SMART method achieves one of the highest reported median survival outcomes for malignant pleural mesothelioma.
Palliative Radiation Therapy
Patients with mesothelioma can receive palliative treatment at any time after diagnosis. Patients with stage 3 or stage 4 mesothelioma may be more frequently treated with palliative radiation therapy. During these stages, doctors use radiation to shrink the tumor and relieve symptoms.
Tumors in these stages can press on the lungs and abdominal organs, causing pain and difficulty breathing. Radiation can help improve these symptoms.
Types Of Radiation Therapy
There are two main types of radiation treatments for mesothelioma: external beam radiation (EBRT) and internal radiation therapy. The benefits and risks are different for each. Patients should discuss options with their medical team.
External Beam Radiation Therapy (EBRT)
External beam radiation therapy is a non-invasive procedure. EBRT uses high-intensity radiation beams to target malignant mesothelioma. A computer guides the beam. Computer guidance helps radiation avoid healthy tissue while targeting cancer cells.
Anesthesiologists may recommend specific forms of EBRT such as 3-D shielded radiation or intensity modulated radiation.
Standard 3-D Radiation Therapy (3DCRT)
3-D imaging radiotherapy (3DCRT) uses imaging scans to plan and deliver treatment. Doctors may include CT, MRI, or PET scans in this planning process. These scans allow the computer to precisely target the radiation beams according to the shape of the tumor.
By precisely targeting the tumor, 3DCRT can deliver a higher dose of radiation and spare healthy tissue.
Research Focus: Standard 3-D Radiation Therapy For Pleural Mesothelioma
A 2016 study investigated radiation therapy in patients with pleural mesothelioma. Doctors have prescribed multimodal treatment. The treatment consisted of chemotherapy followed by an epidural resection followed by 3DCRT. Of the patients, 17 completed all three courses of treatment, while 13 stopped after surgery.
The researchers found that patients who completed all three treatments had the best results. The median survival of patients who completed all three courses of treatment was 39.4 months. The median survival time for patients without radiotherapy was 11.4 months.
In this study, 3DCRT significantly improved survival in pleural mesothelioma.
Note: International Journal of Clinical Oncology
Intensity-Modulated Radiation Therapy (IMRT)
Intensity-modulated radiation therapy (IMRT) is a form of 3DCRT. Doctors often use IMRT to treat pleural mesothelioma. IMRT targets the radiation beams at the tumor tissue from many different directions. However, IMRT uses a larger number of smaller beams than 3DCRT.
By using more beams, IMRT can vary the intensity of each beam. This allows doctors to target higher doses of radiation to certain parts of the tumor. The unique properties of IMRT could allow doctors to kill cancer more precisely while minimizing damage to healthy tissue.
Research Focus: Surgery For Malignant Pleural Mesothelioma After Radiation Therapy (SMART) Clinical Trial
The SMART study investigated a novel approach to radiation therapy in mesothelioma. Instead of treating patients with radiation after surgery, SMART investigated radiation before surgery .
Over the course of 11 years, 96 eligible patients were treated with the SMART regimen. All patients had previously untreated pleural mesothelioma and were in good health. The patient is given a high-intensity modulated dose of radiation to the cancerous area of ??the chest.
After that, the patient underwent radical surgery within a week from the end of radiation. This surgery includes an epidural pleurodesis (EPP). COPD removes the pleura (pleura) and the entire affected lung. BPTNMT can also remove cancerous parts of the diaphragm and pericardium (pericardium).
The median survival time was 24.4 months. However, survival rates by cell type were different.
In patients with epithelial cell type, median survival was 42.8 months.
According to experts, the SMART protocol brings good results in the early and long term. However, this protocol has many risks. The initial radiation treatment caused severe lung damage, by design. This requires quick surgery to remove the damaged lung.
Overall, the SMART protocol is a technically challenging treatment for physicians and surgeons. The study authors recommend that the treatment be used only in specialist cancer centers with significant surgical experience.
Source: The Lancet
Systemic Stereotactic Radiation Therapy (SBRT)
Stereotactic body radiation (SBRT) is an enhanced form of IMRT. SBRT uses a higher dose of radiation in a smaller number of treatments than IMRT. Therefore, SBRT requires more precision in therapy planning and implementation.
According to experts, SBRT can offer several advantages over IMRT. SBRT may be more effective at killing cancer cells and less likely to damage normal tissue. SBRT also requires fewer treatments, potentially making it a more economical therapy.
Focus Of The Study: Stereotactic Body Radiation (SBRT) For Pleural Mesothelioma
A recent study investigated SBRT in patients with recurrent pleural mesothelioma . The study included 21 patients, of which 18 had undergone a previouspleural resection/joint surgery.Three other patients were initially treated with systemic chemotherapy. All patients in the baseline study responded well to therapy. Over time, these patients have limited cancer recurrence or progression.
The study physicians treated these patients with SBRT. At the 12-month follow-up, 75% of treated tumors had not progressed. Median survival was 29 months. Median survival was measured from the time of SBRT treatment, not from the time of diagnosis. Thus, the patients in this study achieved significant survival.
According to the study authors, this treatment achieves high local control with low toxicity and promising survival.
Internal Radiation Therapy
Internal radiation therapy may be called brachytherapy. This type of radiation uses a medically implanted device to deliver cancer-killing energy to tumors. Brachytherapy treats cancer locally, affecting only tissues relatively close to the implant(s).
Brachytherapy uses an implant of beads, ribbons, or capsules to deliver radiation. These implants can stay in the body indefinitely. The implants can also be removed after a while.
According to PubMed, only two medical studies have addressed brain and mesothelioma therapy in the past decade. However, other forms of radiation appear frequently in mesothelioma studies. Therefore, brachytherapy is rarely used in mesothelioma.
Radiation Process And Experience
Each patient’s radiation therapy experience will depend on a few factors. The site of treatment, the specific type of radiation therapy, and the stage of the patient’s cancer can all play a role.
Radiation therapy for mesothelioma usually occurs once a day on weekdays. This treatment can go on for a week. Treatment can also take several weeks.
For example, the EBRT process might include the steps listed below.
External Beam Radiation Therapy (EBRT) Procedure
- Planning session: EBRT requires careful planning. This means that the patient will have one or two appointments for this process. The radiation team might call this a tick session. During this time, the patient will lie very still. Radiologists will erect pillows or body frames to help the patient maintain the best posture. Once located, the healthcare provider will use a marker or small tattoo to mark the treatment site. The radiation team will use the patient’s location and information about the tumor to design the best possible treatment.
- Treatment: The patient will lie on the table in the same position identified during the planning session. The radiation machine, a linear accelerator, can orbit the patient’s body. During the treatment, the machine will make a humming sound. The treatment takes about 10 to 30 minutes. The treatment usually happens once a day for several days in a row. Total can last several weeks.
Patients taking SBRT may have a slightly different treatment experience. For example, SBRT may require fewer treatments than EBRT.
Radiation is usually painless during treatment. Some people continue to work during radiation treatment. However, over time and with additional treatments, patients may lose interest in work.
Radiation mesothelioma patients should discuss their recovery with the cancer team. Treatment team members can help patients understand their own condition and what to expect from recovery.
Survival Rate And Prognosis Of Mesothelioma After Radiation
Survival of mesothelioma patients after radiation therapy depends on several factors, including:
- Mesothelioma cell type
- Patient’s overall health
- Mesothelioma stage
- Type of mesothelioma
- Type of radiotherapy treatment
Radiation is not commonly used to treat peritoneal mesothelioma. In other forms of mesothelioma, survival after radiation therapy ranges from about two years to more than ten years.
Survival Of Patients With Mesothelioma Treated With Radiation Therapy
- Treatment: Chemotherapy followed by epidural pleurodesis, then radiotherapy
- Average lifetime: 39.4 months
- Treatment: Cryosurgery plus radiation therapy
- Average life time: 8 months
- Treatment: Surgery followed by three years of intermittent chemotherapy followed by radiation therapy
- Survival without progression: 50 months
- Treatment: Surgery plus radiation with or without chemotherapy
- Survival without progression: Up to 155 months
Patients should discuss their mesothelioma prognosis with members of their treatment team. Anesthesiologists can help patients understand their unique condition and expected survival.
Side Effects Of Radiation On Mesothelioma Patients
All cancer treatments have side effects, including radiation therapy for mesothelioma. However, radiation is a topical treatment. This means it does not have the same systemic effects as a systemic cancer treatment like chemotherapy.
Patients should discuss all possible side effects with their doctor. Patients should report any side effects that arise during treatment.
Common Side Effects Of Radiation Therapy
- Fatigue: Many patients report a loss of energy and extreme fatigue after radiotherapy sessions. This fatigue can also persist for months after treatment ends.
- Hair loss: Patients may experience total body hair loss at the irradiated area.
- Oral problems: During radiation therapy to the head or neck, patients reported several oral symptoms. Dry mouth, inflammation in the mouth, and lack of taste have all been reported.
- Skin problems: Red, dry, flaky, and dark skin are common after radiation therapy.
Skin problems related to radiation treatment may be called radiation dermatitis. These side effects usually go away after treatment ends. In the meantime, patients may find it helpful to treat their skin gently. This may include wearing soft, loose-fitting clothing and protecting the affected area from the sun.
Experts also recommend that patients should rest a lot during radiation therapy. This can help alleviate some of the fatigue that occurs as the body tries to heal after treatment.
Patients should discuss how to manage their specific side effects with their cancer team.
Who Is Eligible For Mesothelioma Radiation Therapy?
A patient’s eligibility for mesothelioma to receive radiation therapy depends on several factors, including:
- Mesothelioma stage at diagnosis
- Patient’s overall health
- Tumor location
Anesthesiologists will consider these factors when deciding which form of radiation, if any, should be given. Patients considering radiation therapy for mesothelioma should consult an experienced oncologist. Their doctor can explain the potential benefits and side effects of radiation treatment.